DMM Varkon® Tutorial
A Beginner's Guide to the Varkon
Parametric Modeling and CAD Application Development System
By David M. MacMillan
The implied unit in all Varkon models is the millimeter. When printing at least to postscript devices Varkon seems extremely accurate in representing the millimeters of the model in real millimeters on the paper. Scale drawings may thus be very accurate.
Care must be taken, however, in printing or plotting to ensure that the scaling is set up as expected. In particular, although the "Autoplot" function is easy to use and fits drawings to the output device, in order to do this it modifies the output's scale as it sees fit.
For output at known scales, either the "Manual Plot" function or the method of generating a plot file (.PLT file) and manually converting it's format and printing it must be used.
It is also possible to use Varkon to some extent when working in other units, although certain complications can arise.
Decimal Inches
Other decimal unit systems should work relatively transparently. For instance, if you're working in decimal inches, just pretend that the basic unit in Varkon is the inch rather than the millimeter. Then, when printing, reduce the drawing's scale by a factor of 25.4. This could be done after generating a plot file by using the printer driver. For example:
postscript < inchmodel.PLT > inchmodel.ps -x25.4
(There are exactly 25.4 millimeters per inch, so if our default unit is being thought of as an inch we need to expand the natural print size of this unit (1 mm) to 1 inch.)
Using this method, text would shrink as well as the graphics, so care would have to be taken to ensure that the original text was also proportioned in these "virtual inches."
Fractional Inches
With some contortion, fractional inch systems could be handled as well. Fractional inches (e.g. 9/16ths) are still used to an uncomfortably large degree in the US, despite their incredible difficulty of use. Still, certain projects using components dimensioned in nominal fractional inches are best represented in these units. To use fractional inches in Varkon, it would seem to me possible to consider the basic Varkon unit (1 mm, really) as if it were the smallest fractional inch unit in use (e.g., 1/32 inch). It would then be possible to compute a conversion factor to produce accurately scaled output. This system would involve some awkwardnesses - for example, 1.50 inches would be expressed in this example as 48 (32/32 + 16/32). Still, it could be done.
With the exception of any material noted as being in the public domain, the text, images, and encoding of this document are copyright © 1998 by David M. MacMillan.
The author has no relationship with Microform AB, and this Tutorial is neither a product of nor endorsed by Microform AB.
"Varkon" is a registered trademark of Microform AB, Sweden.
This document is licensed for private, noncommercial, nonprofit viewing by individuals on the World Wide Web. Any other use or copying, including but not limited to republication in printed or electronic media, modification or the creation of derivative works, and any use for profit, is prohibited.
This writing is distributed in the hope that it will be useful, but "as-is," without any warranty of any kind, expressed or implied; without even the implied warranty of merchantability or fitness for a particular purpose.
In no event will the author(s) or editor(s) of this document be liable to you or to any other party for damages, including any general, special, incidental or consequential damages arising out of your use of or inability to use this document or the information contained in it, even if you have been advised of the possibility of such damages.
In no event will the author(s) or editor(s) of this document be liable to you or to any other party for any injury, death, disfigurement, or other personal damage arising out of your use of or inability to use this document or the information contained in it, even if you have been advised of the possibility of such injury, death, disfigurement, or other personal damage.
All trademarks or registered trademarks used in this document are the properties of their respective owners and (with the possible exception of any marks owned by the author(s) or editor(s) of this document) are used here for purposes of identification only. A trademark catalog page lists the marks known to be used on these web pages. Please e-mail dmm@lemur.com if you believe that the recognition of a trademark has been overlooked.
Version
1.3, 1998/06/17.
Feedback to dmm@lemur.com
http://www.database.com/~lemur/vk-units.html
Go to the: